**15**

*Answers to Eiffel Tower and other puzzles*

1. For solving this problem, we use the property of similar
figures that the volumes of similar figures are to one another as the cubes
of their heights, provided both are made of the same material.

Therefore, here the volume of the model is 1/8,000,000 of the volume of the
tower. Hence, the height of the model must be (1/8,000,000)^1/3 = 1/200 times
shorter. The height of the tower is, therefore, 300/200 = 1.5 m.

2. The mother should get half of what the son gets and double if what the daughter gets. Let the daughter's share be n.Therefore, the mother's share is 2n and the son's share is 4n. Hence the daughter, son and mother get 1/7th, 4/7th and 2/7th of the man's property.

3. Let n be the number of days in which he typed. Then, he typed
45000n words.

Therefore the total number of words = 45000n+7000+3000

Average rate was 40000 words a day for n+2 days.

Now, 40000(n+2) = 45000n + 10000

n = 14

Hence, the total number of days = 14+2 = 16

4. Let C.P.= x y , therefore S.P.= y x

(10y + x) - (10x + y) = 10x + x + y

2y = 5x

For y to be a single digit, x=2 and y=5. Therefore C.P.=25 and S.P.=52.

Profit = 52 - 25 = 27.

**- Vinaya Kini
(Epsilon) **

Principal's desk | Editor's diary | Message | Ex-member letter | Groups & members | Spirit of maths | Human computer | Hum maths club mein rahte hein | The amusing number | Magic numbers! | Secret codes | Maths exam of a poor student | Peculiarity of the number 65 | Fascinating world of maths | Melodious seven | Eiffle tower | Early bird | Opinions | Answers | Solution to 'the amusing number' | Credits | Memorablia